1. Field of the Invention
This invention relates to a method and a device for separating from sheet metal a product which is connected to the sheet metal through a small joint such as a connecting web or micro-joint, and to a die tool used in a punch press for separating a product from sheet metal.
2. Description of the Prior Art
Conventionally, when one or more than two products are contoured in a piece of sheet metal and separated from the sheet metal, the contoured products are generally not cut off from the sheet metal, but connected to the sheet metal through one or more than two connecting webs or micro-joints.
When the products are connected to the sheet metal through connecting webs, subsequent cutting to cut the webs by a cutting machine is necessary to separate the product from the sheet metal. When the products are cut off from the sheet metal, they are positioned in turn in a cutting zone of the cutting machine. The positioning of the product or the sheet metal with precision in the cutting zone, however, becomes difficult when some products are cut off, since the sheet metal loses its strength and deforms because of openings thereby caused.
When the products are connected to the sheet metal through micro-joints, subsequent mechanical or manual hammering or vibrating must be carried out with respect to the sheet metal. In this case, damages such as cuts, bents, and depressions may be caused on the products.
In any case of the above-mentioned connecting web joints or micro-joints, separating from the sheet metal the products makes much noise.